1. Field of the Invention
The present invention relates to an information recording medium, such as an optical disc or the like, an information recording apparatus for recording record information onto the information recording medium, and an information reproducing apparatus for reproducing the record information recorded on the information recording medium. More particularly, it relates to an information recording medium on which reproduction control information to control a reproduction of the recorded record information is recorded together with the record information, an information recording apparatus for recording the reproduction control information together with the record information onto the information recording medium, and an information reproducing apparatus for reproducing the record information recorded on the information recording medium.
2. Description of the Related Art
In recent years, a technique-has been developed, which increases a recording capacity on an information recording medium such as an optical disc or the like and records one entire movie on one sheet of optical disc for example. As a result, a so-called DVD having a recording capacity equal to about seven times as that of a-conventional CD (Compact Disc) is put into a practical use.
Then, as this DVD, in addition to a so-called DVD video to record the above-mentioned movie, a so-called DVD audio to record only voice information and tone information other than voice information such as accompaniment information and the like is also put into a practical use (hereafter, the voice information and the tone information are collectively referred to as xe2x80x9caudio informationxe2x80x9d).
Here, in a case of the DVD audio, audio information to be recorded on the DVD audio (which is a disc recorded by a DVD audio format) may be non-compressed audio information such as a so-called PCM (Pulse Code Modulation) and the like, for example. This case has a problem that, if a quantization bit number and a sampling frequency are increased, the audio information may become vast so that a music composition of a long time cannot be recorded on one sheet of DVD audio.
So, a method of recording the audio information onto the DVD audio after compressing non-compressed raw or original audio information may be tried.
As a method of compressing the raw audio information, there are one method of setting the compressed audio information, which is generated as a result of the compression, to be a fixing rate, and another method of setting the compressed audio information to be a variable rate. It is thought that the latter so-called variable length compression method can further improve the recording density in consideration that a characteristic of the raw audio information to be compressed (actually, for example, an information amount within a unit time) is changed from time to time in one raw audio information.
However, for example, if performing a fast forward reproduction or a fast backward reproduction on the DVD audio on which the compressed audio information, which is variable-length-compressed, is recorded as a variation in the reproduction control (which is actually an intermittently fast forward reproduction or fast backward reproduction for repeating the operation of performing a forward jump or a backward jump onto the compressed audio information to be reproduced several sec. (seconds) before or after the compressed audio information which is currently being reproduced, and then reproducing the compressed audio information several sec. before or after for a short time duration (for example, 0.2 sec.), and hereafter, both of the intermittently fast forward reproduction and the intermittently fast backward reproduction are collectively referred to as an xe2x80x9cintermittent reproductionxe2x80x9d), it is difficult to perform the conventional operation of searching the information several sec. before or after since the recorded compressed audio information itself is compressed in the variable length.
That is, if the compression method is carried out at the fixed rate, it is possible to multiply an information amount per the unit time by a time duration to be jumped, to thereby search a position to be jumped. However, if the compression method is carried out at the variable rate, since the information amount per the unit time is variable, a search for the position to be jumped becomes extremely complex. This results in a problem that the fast forward reproduction or the fast backward reproduction or the like cannot be practically carried out, which reduces the variation at the time of reproducing the compressed audio information and extremely drops the flexibility or versatility in the reproduction.
The present invention is proposed in diagram of the above mentioned problems. It is therefore an object of the present invention to provide an information recording medium which can variable-length-compress the raw audio information so as to record a music composition of a long time and also increase a variation in the reproduction manner of the compressed audio information to thereby improve the flexibility in the reproduction, an information recording apparatus for recording the compressed audio information onto the information recording medium, and an information reproducing apparatus for reproducing the compressed audio information recorded on the information recording medium.
The above object of the present invention can be achieved by an information recording medium such as a DVD or the like on which record information comprising information units, each including partial audio information obtained by dividing compressed audio information obtained by applying a variable length compression onto raw audio information, is recorded, wherein (i) the information unit includes header information and lead data which is the compressed audio information positioned at a lead of one or a plurality of the partial audio information, and (ii) the header information includes: reproduction time control information such as a PTS (Presentation Time Stamp) or the like indicative of a time of reproducing the partial audio information, to which first lead data among the lead data included in the information unit together with the header information belongs; forward position information such as a forward search pointer or the like indicative of a position on the information recording medium, at which the compressed audio information to be reproduced a first predetermined time duration after a reproduction time indicated by the reproduction time control information on a reproduction time axis of the compressed audio information is recorded; and backward position information such as a backward search pointer or the like indicative of a position on the information recording medium, at which the compressed audio information to be reproduced a second predetermined time duration before the reproduction time on the reproduction time axis is recorded.
According to the information recording medium of the present invention, even if the information amounts of the compressed audio information included in the respective information units are different from each other due to the variable-length-compression, it is possible to speedily search the compressed audio information at a desirable position by controlling the reproduction by use of the forward position information or the backward position information at the time of reproduction.
Therefore, even in case of variable-length-compressing the raw audio information, recording it and reproducing it in order to increase the information amount recordable on the information recording medium, it is possible to perform a fast forward reproduction or a fast backward reproduction for example, or perform a reproduction of the compressed audio information with designating in advance the compressed audio information to be reproduced, by speedily searching the partial audio information corresponding to the forward position information or the partial audio information corresponding to the backward position information. Hence, it is possible to improve the flexibility in reproducing the compressed audio information.
By these, it is possible to improve the recording capacity of the raw audio information by variable-length-compressing the raw audio information and recording it while keeping the improved flexibility at the time of reproduction as a result.
In one aspect of the information recording medium of the present invention, the forward position information is relative position information indicative of a position on the information recording medium of the information unit, in which the lead data to be reproduced the first predetermined time duration after is recorded, with respect to a position on the information recording medium of the information unit, in which the forward position information is recorded, and the backward position information is relative position information indicative of a position on the information recording medium of the information unit, in which the lead data to be reproduced the second predetermined time duration before is recorded, with respect to a position on the information recording medium of the information unit, in which the backward position information is recorded.
According to this aspect, since the forward position information and the backward position information are recorded respectively as the relative position information, it is possible to respectively express the forward position information and the backward position information with an almost minimum information amount.
Therefore, it is possible to increase the recording capacity of the compressed audio information to be primarily recorded, and a music composition search or the like can be speedily performed.
In another aspect of the information recording medium of the present invention, each of the first predetermined time duration and the second predetermined time duration is 1 sec. (second).
According to this aspect, it is possible to perform various reproduction controls such as a fast forward reproduction etc., by searching the compressed audio information efficiently without deteriorating the natural auditory sense at the time of reproduction-controlling the compressed audio information.
In another aspect of the information recording medium of the present invention, the record information has a physically hierarchical structure with the information unit as a bottom layer.
According to this aspect, it is possible to search the partial audio information corresponding to the forward position information and the partial audio information corresponding to the backward position information even more efficiently.
In this aspect, management information, which is reproduction control information with regard to whole of the compressed audio information, may be recorded at a lead of the record information corresponding to a top layer of the hierarchical structure.
By constructing in this manner, it is possible to speedily search the compressed audio information by effectively using the management information as well as the forward position information and the backward position information.
Further in this case, the compressed audio information may include one or a plurality of music composition information, and the management information may include: music composition address information to search the compressed audio information with the music composition information as a unit; and music composition reproduction time duration.information indicative of a reproduction time duration in case of reproducing the compressed audio information with the music composition information as a unit.
By constructing in this manner, by using the management information as well as the forward position information and the backward position information, it is possible to perform the search for each of the music compositions, and perform the partial search, the partial fast forward reproduction or the partial fast backward reproduction within one music composition.
The above object of the present invention can be also achieved by an information recording apparatus for recording record information onto an information recording medium such as a DVD audio or the like, the record information comprising information units, each being obtained by dividing compressed audio information obtained by applying a variable length compression onto raw audio information and each including the compressed audio information and header information. The information recording apparatus is provided with: a reproduction control information generation device such as a signal process unit or the like for generating reproduction control information used for reproducing the compressed audio information included in the information unit together with the header information; a forward position information generation device such a signal process unit or the like for generating forward position information indicative of a position on the information recording medium, at which the compressed audio information to be reproduced a first predetermined time duration after on a reproduction time axis of the compressed audio information is recorded; a backward position information generation device such as a signal process unit or the like for generating backward position information indicative of a position on the information recording medium, at which the compressed audio information to be reproduced a second predetermined time duration before on the reproduction time axis; and a recording device such as a mastering device or the like for recording the generated reproduction control information, the generated forward position information and the generated backward position information as the header information onto the information recording medium.
According to the information recording apparatus of the present invention, since the forward position information and the backward position information are respectively recorded in the header information recorded within the information unit together with the compressed audio information, even if the information amounts of the compressed audio information included in the respective information units are different from each other due to the variable-length-compression, it is possible to speedily search the compressed audio information at a desirable position by controlling the reproduction by use of the forward position information or the backward position information at the time of reproduction.
Therefore, even in case of variable-length-compressing the raw audio information, recording it and reproducing it in order to increase the information amount recordable on the information recording medium, it is possible to perform a fast forward reproduction or a fast backward reproduction for example, or perform a reproduction of the compressed audio information with designating in advance the compressed audio information to be reproduced, by speedily searching the partial audio information corresponding to the forward position information or the partial audio information corresponding to the backward position information. Hence, it is possible to improve the flexibility in reproducing the compressed audio information.
By these, it is possible to improve the recording capacity of the raw audio information by variable-length-compressing the raw audio information and recording it while keeping the improved flexibility at the time of reproduction as a result.
In one aspect of the information recording apparatus of the present invention, each of the first predetermined time duration and the second predetermined time duration is 1 sec. (second).
According to this aspect, it is possible to perform various reproduction controls such as a fast forward reproduction etc., by searching the compressed audio information efficiently without deteriorating the natural auditory sense at the time of reproduction-controlling the compressed audio information.
The above object of the present invention can be also achieved by a first information reproducing apparatus for reproducing compressed audio information from the above described information recording medium of the present invention. The first information reproducing apparatus is provided with: a detecting device such as an optical pickup or the like for detecting one forward position information; a reproducing device such as an audio decoder or the like for reproducing at least one portion of the compressed audio information, which is recorded on the information recording medium at a position indicated by the detected one forward position information; a controlling device such as a system controller or the like for controlling, the detecting device and the reproducing device to repeat (i) detecting another forward position information recorded within the information unit, in which the reproduced compressed audio information is included, as new forward position information and (ii) reproducing at least one portion of the compressed audio information recorded on the information recording medium at a position indicated by the new forward position information.
According to the first information reproducing apparatus of the present invention, since the operations of detecting the forward position information, reproducing at least one portion of the compressed audio information recorded on the information recording medium at the position indicated by the detected forward position information and further detecting the forward position information recorded together with the reproduced compressed audio information, it is possible to speedily perform the fast forward reproduction of the compressed audio information which is variable-length-compressed.
Therefore, even in case of variable-length-compressing the raw audio information, recording it and reproducing it in order to increase the information amount recordable on the information recording medium, it is possible to perform a fast forward reproduction by speedily searching the partial audio information corresponding to the forward position information. Hence, it is possible to improve the flexibility in reproducing the compressed audio information.
By these, it is possible to improve the recording capacity of the raw audio information by variable-length-compressing the raw audio information and recording it while keeping the improved flexibility at the time of reproduction as a result.
The above object of the present invention can be also achieved by a second information reproducing apparatus for reproducing compressed audio information from the above described information recording medium of the present invention. The second information reproducing apparatus is provided with: a detecting device such as an optical pickup or the like for detecting one backward position information; a reproducing device such as an audio decoder or the like for reproducing at least one portion of the compressed audio information, which is recorded on the information recording medium at a position indicated by the detected backward position information; a controlling device such as a system controller or the like for controlling the detecting device and the reproducing device to repeat (i) detecting another backward position information recorded within the information unit, in which the reproduced compressed audio information is included, as new backward position information and (ii) reproducing at least one portion of the compressed audio information recorded on the information recording medium at a position indicated by the new backward position information.
According to the second information reproducing apparatus of the present invention, since the operations of detecting the backward position information, reproducing at least one portion of the compressed audio information recorded on the information recording medium at the position indicated by the detected backward position information and further detecting the backward position information recorded together with the reproduced compressed audio information, it is possible to speedily perform the fast backward reproduction of the compressed audio information which is variable-length-compressed.
Therefore, even in case of variable-length-compressing the raw audio information, recording it and reproducing it in order to increase the information amount recordable on the information recording medium, it is possible to perform a fast backward reproduction by speedily searching the partial audio information corresponding to the backward position information. Hence, it is possible to improve the flexibility in reproducing the compressed audio information.
By these, it is possible to improve the recording capacity of the raw audio information by variable-length-compressing the raw audio information and recording it while keeping the improved flexibility at the time of reproduction as a result.
The above object of the present invention can be also achieved by a third information reproducing apparatus for reproducing compressed audio information from one of the aspects of the above described information recording medium of the present invention, wherein the record information has a physically hierarchical structure with the information unit as a bottom layer, wherein management information, which is reproduction control information with regard to whole of the compressed audio information, is recorded at a lead of the record information corresponding to a top layer of the hierarchical structure, and wherein the compressed audio information includes one or a plurality of music composition information, and the management information includes: music composition address information to search the compressed audio information with the music composition information as a unit; and music composition reproduction time duration information indicative of a reproduction time duration in case of reproducing the compressed audio information with the music composition information as a unit. The third information reproducing apparatus is provided with: a first detecting device such as an optical pickup or the like for detecting the management information corresponding to the music composition information to be reproduced; a searching device such as a system controller or the like for searching a position on the information recording medium of the music composition information to be reproduced on the basis of the detected management information; a second detecting device such as an optical pickup or the like for detecting at least one of the forward position information and the backward position information within the information unit recorded at the searched position; and a reproducing device such as an audio decoder or the like for searching a reproduction start position within the music composition information to be reproduced by using at least one of the detected forward position information and the detected backward position information, and reproducing the compressed audio information recorded at the searched reproduction start position.
According to the third information reproducing apparatus of the present invention, it is possible to speedily reproduce the compressed audio information at the reproduction start position of the music composition information by utilizing the forward position information and the backward position information as well as the management information corresponding to the music composition information to be reproduced.
Therefore, even in case of variable-length-compressing the raw audio information, recording it and reproducing it in order to increase the information amount recordable on the information recording medium, it is possible to perform the reproduction of the compressed audio information to be reproduced which is designated in advance. Hence, it is possible to improve the flexibility in reproducing the compressed audio information.
By these, it is possible to improve the recording capacity of the raw audio information by variable-length-compressing the raw audio information and recording it while keeping the improved flexibility at the time of reproduction as a result.
The above object can be achieved by a fourth information reproducing apparatus for reproducing compressed audio information from one of the aspects of the above described information recording medium of the present invention, wherein the record information has a physically hierarchical structure with the information unit as a bottom layer, wherein management information, which is reproduction control information with regard to whole of the compressed audio information, is recorded at a lead of the record information corresponding to a top layer of the hierarchical structure, and wherein the compressed audio information includes one or a plurality of music composition information, and the management information includes: music composition address information to search the compressed audio information with the music composition information as a unit; and music composition reproduction time duration information indicative of a reproduction time duration in case of reproducing the compressed audio information with the music composition information as a unit. The fourth information reproducing apparatus is provided with a designating device such as an input device or the like for designating music composition information to be reproduced and an elapse time from a lead of the music composition information; a first detecting device such as an optical pickup or the like for detecting the management information corresponding to the designated music composition information; a searching device such as a system controller or the like for searching a position on the information recording medium of the designated music composition information on the basis of the detected management information; a second detecting device such as an optical pickup or the like for detecting at least one of the forward position information and the backward position information within the information unit recorded at the searched position; and a reproducing device such as an audio decoder or the like for searching a reproduction start position corresponding to the designated elapsed time from the lead of the designated music composition information by using at least one of the detected forward position information and the detected backward position information, and reproducing the compressed audio information recorded at the searched reproduction start position.
According to the fourth information reproducing apparatus of the present invention, it is possible to speedily reproduce the compressed audio information at the position corresponding to the elapsed time from the lead of the music composition information, by utilizing the forward position information and the backward position information as well as the management information corresponding to the designated music composition information.
The nature, utility, and further features of this invention will he more clearly apparent from the following detailed description with respect to preferred embodiments of the invention when read in conjunction with the accompanying drawings briefly described below.